The present invention relates to a method for controlling the operation of an LED luminaire, and to an LED luminaire designed for this purpose. In particular, the invention in this case relates to so-called retrofit LED luminaires, that is to say LED luminaires which are designed such that they can be used as an incandescent bulb substitute or a low-voltage or 12-volt halogen lamp substitute.
Incandescent lamps and halogen lamps in which the original light source is replaced by gas discharge lamps or LEDs are being used increasingly, and are available from various manufacturers. In this case, the production of a pleasant light represents a particular requirement. In particular, a pleasant color temperature is required. In this case, a color temperature which appears to be pleasant can be chosen as a function of various constraints. For work, for example, a cooler light is preferred while, in contrast, a warm color temperature is generally found to be more pleasant for leisure purposes. Furthermore, a different color temperature can lead to different color reproduction. A specific color temperature may accordingly be advantageous depending, for example, on the dwelling facility. Overall, an individually adjustable color temperature can therefore be considered desirable.
Virtually fundamentally, a normal building has the same power supply means. The power supply means for illumination in this case consists of wiring, which carries the mains AC voltage and is laid in walls and ceilings such that connection facilities for luminaires are located at predetermined points on the ceilings and walls.
This wiring has switches for the user to control these lamps, that is to say to switch the electric current that is supplied on and off. These are normally on/off switches, that is to say toggle switches, which provide two different values (on and off) in two different positions of a toggle, and switches which act as momentary-contact switches or pushbuttons. The latter have only one possible position, with the currently selected value being changed by pushing the pushbutton (a lamp which is switched off is switched on by pushing, for example).
A further option in existence is dimming switches, which have the same features as pushbuttons or switches and can additionally dim the lamp by turning the dimming switch in a sideways direction. The dimming is normally carried out by varying the voltage profile (for example by means of so-called phase on-gating or phase off-gating) or the power. These dimming switches are normally formed by electronic circuits and in this case also contain electronic switches such as diacs, triacs, thyristors or MOSFETs. In modern power supply means, such as those used in relatively modern buildings, the lighting can also be dimmed continuously via a dimming pushbutton which, in addition to the rotatable dimming switch, represents a further embodiment of a dimming switch for continuous, that is to say infinitely variable, brightness variation. In this case, a lamp which is switched off is switched on by briefly pressing once. As normal, this lamp can now be switched off by briefly pressing once again. However, if the pushbutton is pushed for a relatively long time with the lamp in the switched-on state, then the lamp is dimmed. This means that the lighting intensity of the at least one connected lamp decreases slowly but continuously. The current dimming level is maintained when the pushbutton is released again. The dimming value therefore oscillates cyclically if the pushbutton is pressed continuously.
In summary, a switch such as this can therefore be regarded as a user interface for the lighting system consisting of wiring and at least one luminaire.
Furthermore, a switching actuator which is controlled via a bus could also be used as a switch or dimming switch.
Furthermore, the power for a conventional lighting system may be supplied in the low-voltage range. This is the case in particular when using halogen lamps. A mains switching unit is for this purpose connected to the wiring which carries the main alternating current, and is generally mounted on the ceiling or on the wall, in the vicinity of the halogen luminaires. The mains switching unit now converts the mains AC voltage to a low-DC voltage, and thus supplies the one or more halogen lamps, often via exposed lines. The already installed switch is once again used for user control, in which case a dimming switch can likewise be used to dim the halogen lighting system.
In the situation in which the power supply means in the building cannot have a dimming switch, it is nevertheless desirable to dim the lighting. Lamps have been developed for this situation, such as the “Dulux L Vario” lamp type from the OSRAM Company, which can be screwed into conventional lamp sockets and can be operated using 230 volts AC voltage. In this case, as a light source, the lamp has a gas discharge lamp, and has additional electronics, which are designed for operation of the light source in various modes. The various modes in this case correspond to different brightnesses. When the lamp is switched on for the first time or after having been switched off for a relatively long time, it is first of all operated at 20 watts. If the lamp is now switched off again and is switched on again within three seconds, it is now operated with a power of only 8 watts. A lamp such as the Osram Dulux L Vario therefore allows stepped dimming, in which different discrete dimming values can be set by means of a conventional light switch, by switching it on and off repeatedly.
Because of the positive characteristics of LEDs and OLEDs, and their continual technical further developments, there is an increasing demand for light sources which have LEDs or OLEDs.
Because of the requirements described above, the invention is based on the object of providing a method for controlling the operation of an LED luminaire, as well as an LED luminaire which is designed for this purpose, in which individual settings, in particular of the color temperature, are possible, and which can nevertheless be operated and controlled using conventional power supply means.
The object is achieved by the features of the independent claims. The dependent claims develop the central concept of the invention in a particularly advantageous manner. The invention therefore relates to a method for controlling the operation of an LED luminaire which has a plurality of LEDs as light sources. The method in this case has the following steps: firstly, a control unit evaluates the LED luminaire, by evaluating an electrical signal which is produced by a switch, pushbutton or dimming switch. The switch, pushbutton or dimming switch is in this case supplied with current. In this case, the signal is produced by the user, by operating the switch, pushbutton or dimming switch. Furthermore, the switch, pushbutton or dimming switch is connected to the control unit for the LED luminaire via an interface. In the second step, the color spectrum of the LED luminaire is varied. This variation is carried out as a function of the evaluated signal.
The control unit preferably evaluates the number and/or the time duration of the operation of the switch, pushbutton or dimming switch. Additionally or alternatively, when using a dimming switch, the control unit evaluates the voltage which is passed on from the dimming switch, and/or its time profile.
The LED luminaire may produce white light. The color temperature of this white light may be varied as a function of the evaluated signal.
The color reproduction index of the light from the LED luminaire can likewise be varied as a function of the evaluated signal.
At least one of the LEDs is preferably operated with pulse-width modulation. In this case, the duty ratio of the pulse-width modulation can be varied as a function of the evaluated signal.
Furthermore, it is feasible for the signal also to be evaluated for brightness control of the LED luminaire.
Modulated mains voltage signals can be supplied to the interface through a switch, pushbutton or dimming switch. The mains voltage signals may, for example, be modulated such that the mains voltage is interrupted for a certain time period, or is passed on only for a certain time period. These time periods may also be repeated a number of times. However, the mains voltage signals may, for example, also be modulated by application of higher-frequency signals, for example the use of a phase on-gating dimmer or a phase off-gating dimmer makes it possible to transmit a voltage which is composed of a frequency component of the normal mains voltage (for example 50 Hz) and of higher harmonics (that is to say by way of example, the third, fifth and seventh harmonics). The higher-frequency signals may, however, also be produced by modulation of a higher-frequency control signal (for example by inductive coupling).
In a further aspect, the control unit sends commands, for example in accordance with the DALI Standard, via the same interface or possibly via a further interface. It can preferably receive digital commands in the same manner.
The invention furthermore relates to a control unit, in particular an integrated circuit such as an ASIC or a microcontroller, which is designed to implement a method as described above.
Furthermore, the invention relates to an LED luminaire. This has a supply circuit which supplies a plurality of LEDs, as light sources, from a supply voltage. Furthermore, it comprises a control unit which is designed to evaluate signals which are produced by a switch, pushbutton or dimming switch which can be operated by a user and is connected to the control unit and supplied with voltage via an interface of the LED luminaire. In this case, the control unit is also designed to vary the color spectrum of the LED luminaire as a function of the evaluated signal.
Preferably, the control unit is designed to evaluate the number and/or the time duration of the operation of the dimming switch, switch or pushbutton.
The LED luminaire can produce white light, and the control unit can vary the color temperature of the white light as a function of the evaluated signal.
It is likewise feasible for the control unit to be able to vary the color reproduction index of the light from the LED luminaire as a function of the evaluated signal.
Preferably, the control unit varies (influences) at least one of the LEDs by pulse-width modulation. The duty ratio of the pulse-width modulation can therefore be adjusted as a function of the evaluated signal.
It is also feasible for the control unit to also evaluate the signal for brightness control of the LED luminaire.
The light sources may have at least one RGB-LED module.
It is also possible for the light sources to have at least one dye-converted white LED. In addition, the light sources may have at least one further colored LED. Preferably, the intensities of the white LED and of the further colored LED can be controlled independently of one another by the control unit.
The LED luminaire may be in the form of a retrofit lamp. For this purpose, it may have a halogen or incandescent-lamp cap or halogen lamp pins.
The interface is preferably designed to receive modulated mains voltage signals through a switch, pushbutton or dimming switch. The control unit is preferably designed to adjust the color spectrum of the LED luminaire on the basis of the modulated mains voltage signals. Furthermore, the control unit is preferably designed to receive and/or to transmit digital commands, for example in accordance with the DALI Standard, via the same interface or a further interface.
Finally, the invention relates to an LED lighting system. This has one or more LED luminaires. At least one of these LED luminaires has the features described above. This one LED luminaire is also connected to a dimming switch, switch or pushbutton. This is supplied with voltage.
The dimming switch, switch or pushbutton is preferably supplied with voltage from the LED luminaire, in particular via the interface, or from an external voltage source, in particular a mains voltage.
It is also feasible for the LED luminaire to be supplied with voltage via the switch, pushbutton or dimming switch from an external voltage source, in particular a mains voltage, in which case the LED luminaire supply preferably at the same time forms the interface.
In this case, the switch, pushbutton or dimming switch may be supplied with DC voltage from the LED luminaire, in particular via the interface.
It is also possible to simultaneously also vary the color temperature of the LED luminaire when the brightness is varied. The color temperature is shifted in the direction of a warmer color temperature when the brightness (luminous power) is reduced (or vice versa, that is to say a deliberate variation in the direction of a colder color temperature is also introduced when the brightness is increased).
The color temperature is preferably varied by independent control of at least two light-emitting diodes with different spectra, for example at least one dye-converted white LED and at least one monochromatic LED.
In addition, the LED lighting system may have a central control unit. This is preferably connected to the interface, with the central control unit evaluating commands from the interface and controlling the LED luminaire.
Furthermore, the LED lighting system may have a BUS. The LED luminaires and the central control unit are preferably connected to this BUS. The BUS may also be designed for communication with and/or to supply power to the LED luminaires and the central control unit.